Spark-plug.



H. S. THOMASSUN.

SPARK PLUG. APPLIGATION rmzn 0011.2, 1912.

1,107,634.' Patented Aug. 18, 1914,

ITED .SATES PATENT FFICE.

HIRAM S. THOMASSON, OF PORTLAND, IOWA..

SIARK-PLUG.

Y To all Iwhom it may concern Be it known that I, HIRAM S. TnoMAssoN, a-eitizen of the United States, residing at Portland, in the county of Cerro Gordo and State of Iowa, have invented certain new and useful Improvements in Spark-Plugs; and I do hereby declare the following to be a full, clear, and exact description ot' the inv ention, such as Will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to spark plugs for igniting the charges 'of internal combustion engines by means of electricity; and it consists in the novel construction and combination of the parts hereinafter fully described and claimed.

In the drawings, Figure 1 is a side view of a spark plu constructed according to thisinvention. Ifig. 2 is an end view of the spark plu Fig. 3 is a longitudinal section through t e spark plug.

The body ortion 2 of the spark plug is provided with` a chamber 3 at its inner end, and a screwthreaded portion 4 which is, screwed irito a hole in the engine cylinder or combustion chamber' in the usual way. The outer portion of the plug has achamber 5 which is a little larger in diameter than the chamber. A core 6 of insulating material is provided, and has a collar or enlargement 7 at its middle part which is secured in the chamber 5 by means of a screwthreaded gland 8,-01 other suitable fasteningr device. The front end portion 9 of the core is smaller` in diameter and shorter than the chamber 3, into which it projects, and it has a recess 10 in its inner end, and a hole 1l which ex-V tends longitudinally through its center. The inner end of the plug is arcuate and is provided with a `series of radial slots 14 which form a series of arcuate projections 15. A screwthreaded rod 16 is slidable longitudinally in the hole 11, and is provided with an adjusting nut 17 which is arranged in the recess 10.

A perforated disk 18 is secured to the inner end of the rod 16 and overlaps the pro- Specication of Letters Patent.

p Application lled October 2, 1912.

Patented Aug. 18, 1914. semi No. 723,599.

jections 15. As many perforations 24. as de: sired may be formed in the disk 18, and the nut 17 is arranged so that the disk is held at a suitable distance from the rounded projections to form a seriesof spark a s. `The louter end of the rod 16 is provide Awith a fastening nut 19, and has a nut 21 for con-A necting the rod to a battery wire 20. Each l time currentis sent through the disk and plug, sparks are formed between the projections and the disk, and the inflammable charge in the engine cylinder is ignited. The charge in the chamber 3 is also ignited and it blows out therefrom all accumulations of oil, carbon or other material which would, otherwise block the narrow spaces between the disks and the projections. Several of these spaces may become obstructed without wholly preventing the formation of sparks, and the size and the perfor-ations 24 regulate the cleaning action at the spark ga is, and prevent it from being too violent. he central location of the rod 16 prevents the parte from getting out of adjustment. 1

What I claim is:

In a spark plug, the combination, with a plug body havlng a gas chamber in itsjnner end portion, and a series of slots in its inner end which form electrode projections, ofv a core of insulating materia secured inthe plug body with its outer end portion pro jectmg therefrom, said core having a central hole and having a recess in its inner end portion, a screwthreaded rod which projects through the said core and gas cham er, adjusting nuts screwed on the said rod and securing it in the core, one of the nuts bein arranged in the said recess, and a-vperforate electrode disk secured on the inner end of the said rod and overlapping the said electrode projections and the. gas chamber.

In testimony whereof I have affixed my signature in the presence of two witnesses.

HIRAM S. THOMASSON.

Witnesses:

Manx LEAMAN, A. J. Spsvins.

and number of the vent slots 14' r 

